This invention relates to polyfluorinated aromatic and heterocyclic compounds and methods for their production; specifically, the invention is concerned with compounds which contain sulphurpentafluoride groups.
The preparation and use of various polyfluorinated aromatic and heterocyclic derivatives is well documented in the prior art, and the compounds in question have found widespread use, for example as intermediates in the pharmaceutical industry. Of particular value in this connection are intermediates containing trifluoromethyl groups, especially trifluoromethylbenzene derivatives; a favored end-group in this context is a 3,5-bis(trifluoromethyl)phenyl group which has been developed for use in a range of anti-asthma and anti-arthritis drugs. Such a group may be introduced into a drug molecule by means of a suitable labile group in the 1-position so that, for example, 3,5-bis(trifluoromethyl)bromobenzene is a useful intermediate for the preparation of such drugs.
The present inventors have now found that alternative polyfluorinated derivatives may be obtained by relatively straightforward synthetic procedures to provide a further range of intermediates with potentially widespread industrial applicability, particularly in relation to pharmaceuticals.
Various organic sulphur pentafluorides, and methods for their preparation, have previously been disclosed in PCT Patent Application WO 97/05106. The present inventors have now found that specific derivatives of this type are of particular value in the synthesis of pharmaceuticals; such derivatives comprise trisubstituted compounds comprising at least one sulphur pentafluoride group and at least one labile group.
Thus, according to a first aspect of the present invention, there is provided a polyfluorinated aromatic or heterocyclic compound comprising at least three ring substituents, at least one of which comprises a sulfurpentafluoride group and at least one of which comprises labile group.
Said aromatic or heterocyclic compound may be based on any suitable ring system, but particularly favorable results may be obtained with compounds based on aromatic ring systems such as benzene, naphthalene, anthracene or phenanthrene, with benzene derivates being especially preferred. Of particular value are trisubstituted benzene derivates, substituted in the 1-, 3- and 5-positions.
Said polyfluorinated aromatic or heterocyclic compound comprising at least three ring substituents, at least one of which comprises a sulfurpentafluoride group and at least one of which comprises a labile group preferably includes one or two sulfurpentafluoride groups. Compounds which comprises only one sulfurpentafluoride group typically also comprise a further fluorinated group, preferably a trifluoromethyl group.
The labile group comprises a substituent capable of facilitating further reaction with another compound during, for example, drug production. Suitable reactive groups in the content of the compounds of the present invention are groups which are labile as a result of the powerful electron-withdrawing inductive effect of the polyfluorinated groups in the molecule, typical examples being amino, bromo and nitro groups.
Specifically preferred compounds according to the present invention are (3-amino-5-trifluoromethyl)phenyl) sulfurpentafluoride, (3-bromo-5-trifluoromethyl)phenyl) sulfurpentafluoride, (3-nitro-5-trifluoromethyl)phenyl) sulfurpentafluoride, 3,5-bis(pentafluorosulfuryl)aniline 3,5-bis(pentafluorosulfuryl)bromobenzene and 3,5-bis(pentafluorosulfuryl)nitrobenzene.